Phase change type heat dissipating device

ABSTRACT

A phase change type heat dissipating device for dissipating heat from a heat generating component includes a cavity and a working medium positioned in the cavity. The working medium is a kind of electrically insulated phase change material, and represents solid state at normal temperature. The heat generating component is received in the cavity.

BACKGROUND

1. Technical Field

The present disclosure generally relates to dissipating devices, and more particularly to a dissipating device for removing heat from an electronic component by phase changing.

2. Description of the Related Art

As electronic technology continues to advance, electronic components are made to provide faster operational speeds and greater functional capabilities. When an electronic component operates at a high speed for a long time, its temperature usually increases greatly. It is therefore desirable to provide a heat dissipating device for removing the generated heat quickly.

A traditional dissipating device is disposing a metal radiator on a top of the electronic component. The radiator includes a base contacting with the electronic component and a plurality of fins attached to the base. Heat generated by the electronic component is conducted into the base and dissipated to ambient air from the fins.

With respect to some electronic devices working intermittently, the time of operation under high loading is relative short than the time of standby or the time of operation under low loading. When the electronic device works under high loading, the heat generated by the electronic component in the electronic device is conducted to the air inside a casing of the electronic device quickly via the fins. This leads to a high increasing of the temperature of the casing of the electronic device a short time, and a negative affect of operation for the user. When the electronic device is standby or works under low loading, the heat generated by the electronic component is less, and the fins can not be used efficiently.

Therefore, it is desirable to provide a dissipating device can overcome the above problem.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with reference to the drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present phase change type heat dissipating device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the views.

FIG. 1 is an assembled, isometric view of a phase change type heat dissipating device in accordance with an embodiment of the disclosure.

FIG. 2 is an exploded view of the phase change type heat dissipating device of FIG. 1.

FIG. 3 is a cross sectional view of the phase change type heat dissipating device of FIG. 1, taken along line III-III thereof.

DETAILED DESCRIPTION

Referring to FIG. 1 to FIG. 3, a phase change type heat dissipating device 10 in accordance with an exemplary embodiment is provided for removing heat from a heat generating component 20 of an electronic device (not shown). The phase change type heat dissipating device 10 includes a top cover 11, a bottom plate 12 opposite to the top cover 11 and a working medium 30 between the top cover 11 and the bottom plate 12.

The top cover 11 and the bottom plate 12 are flat. A size of the top cover 11 is greater than that of the bottom plate 12. A plurality of lateral peripheries of the bottom plate 12 extends upward to form sidewalls 13. Top ends of the sidewalls 13 curve and extend horizontally to form lateral walls 131. A periphery of a bottom surface of the top cover 11 is attached to the lateral walls 131, whereby a cavity 14 is formed between the top cover 11 and the bottom plate 12. The bottom plate 12, the sidewalls 13 and the lateral walls 131 are integrally formed as a single piece. The top cover 11, the bottom plate 12, the sidewalls 13 and the lateral walls 131 are made from materials having good heat conductivity, such as aluminum and copper. Alternatively, the top cover 11 and the bottom plate 12 can be a shell of other component (not shown) disposed in the electronic device.

The working medium 30 is received in the cavity 14. The working medium 30 is electrically insulated and phase change material, and represents solid state at normal temperature. A volume of the working medium 30 under the normal temperature is smaller than a volume of the cavity 14. The working medium 30 can be liquefied to liquid at a certain temperature. A melting point of the working medium 30 is between a temperature of the heat generating component 20 under standby/low-loading and the temperature of the heat generating component 20 under high-loading. The working medium 30 can be hydrate, organic acid or esters etc.

When assembled, the heat generating component 20 electrically connected to other components in the electronic device by being mounted on a printed circuit board, such as surface mounted technology (SMT). The cavity 14 encloses the heat generating component 20. The working medium 30 directly contacts the heat generating component 20. In this embodiment, the heat generating component 20 is disposed on the bottom plate 12.

When the heat generating component 20 works under high loading, heat generated by the heat generating component 20 is conducted to the working medium 30 quickly. The working medium 30 close to the heat generated component 20 is heated and liquefied to liquid firstly, then thermal convection is generated to prompt the working medium 30 relatively far from the heat generating component 20 and close to the inner surface of the cavity 14 being heated and liquefied. After that, when all of the working medium 30 is liquefied to liquid, heat is conducted to the inner surface of the cavity 14. In the process of liquefaction, heat can be temporarily stored in the working medium 30 and conducted to the external shell (not shown) of the electronic device slowly. Consequently, the surface of the heat generating component 20 is kept in a comparative low temperature, and the temperature of the external shell is avoided rising too fast in a short time, preventing affecting of the operation for the user.

When the heat generating component 20 is under standby or works under low-loading, since the heat generating capacity of the heat generating component 20 is smaller than the heat dissipation capacity of the working medium 30 and the shell, the working medium 30 keeps conducting heat and exchanging heat to external air. In the above process of operation under high-loading and standby/under low-loading, the working medium 30 is used for conducting and exchanging heat. As a dissipation medium, the working medium 30 can be utilized fully. Due to the insulation characteristic of the working medium 30, the working medium 30 will not affect the working performance of the heat generating component 20.

Alternatively, when the heat generating component 20 is engaged with a circuit board (not shown), the circuit board can be received in the cavity 14. The shape of the top cover 11, and the bottom plate 12 are not limited to flat, and can be other shape, such as triangular pyramid. The shape of the working medium 30 can be designed according to the shape of the cavity 14 for being received in the cavity 14.

In summary, the heat generating component 20 is received in the cavity 14 of the phase change type heat dissipating device 10. The working medium 30 represents solid state at normal temperature. The working medium 30 is in contact with the heat generating component 20. When the heat generating component 20 works under high-loading, heat generated by the heat generating component 20 is conducted to the working medium 30 firstly, the working medium 30 is liquefied gradually for temporarily storing heat. Thus, heat is conducted to the external shell of the electronic device slowly, and the temperature of the external shell is avoided rising too fast in a short time for facilitating the operation of the user. When the phase change type heat dissipating device 10 is under standby or works under low-loading, the working medium 30 keeps conducting heat and exchanging heat to external air. The working medium 30 turns to be solid state gradually for preparing to store heat in temporary in a next high loading status.

It is to be understood that the above-described embodiments are intended to illustrate rather than limit the disclosure. Variations may be made to the embodiments without departing from the spirit of the disclosure as claimed. The above-described embodiments illustrate the scope of the disclosure but do not restrict the scope of the disclosure. 

What is claimed is:
 1. A phase change type heat dissipating device for removing heat from a heat generating component, comprising: a casing enclosing the heat generating component; a working medium received in the casing; wherein the working medium is electrically insulated and phase change material, the working medium represents solid state at normal temperature and is liquefied when the heat generating component works under high loading and the temperature of the heat generating component is higher than the normal temperature.
 2. The phase change type heat dissipating device of claim 1, wherein the working medium is made from hydrate, organic acid or esters.
 3. The phase change type heat dissipating device of claim 1, wherein the heat generating component electrically connects to external power source via printed circuit board or wire.
 4. The phase change type heat dissipating device of claim 1, comprising a top cover and a bottom plate opposite to the top cover, the working medium being disposed between the top cover and the bottom plate.
 5. The phase change type heat dissipating device of claim 4, wherein a plurality of sidewalls extend upward from a periphery of the bottom plate, and lateral walls being curved and extending horizontally from the top ends of the sidewalls, a bottom surface periphery of the top cover being attached to the lateral walls to form the cavity.
 6. The phase change type heat dissipating device of claim 4, wherein the heat generating component is located at the bottom plate.
 7. The phase change type heat dissipating device of claim 1, wherein a melting point of the working medium is between a temperature of the heat generating component under standby/low-loading and a temperature of the heat generating component under high-loading. 